P0585
Cruise Control Multi-Function Input A and B Correlation
Cruise control uses two redundant multiplexed inputs (A and B) for safety. The two inputs do not agree - one reports a button press the other does not, or both report incompatible levels at the same time.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Stalk module ageing - drift between A and BCommon
Parts involved
- Cruise Control Stalk
- Cruise Input B Wiring
P0585 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.